The communications industry is rapidly changing to adjust to emerging technologies and ever increasing customer demand. This customer demand for new applications and increased performance of existing applications is driving communications network and system providers to employ networks and systems having greater speed and capacity (e.g., greater bandwidth). In trying to achieve these goals, a common approach taken by many communications providers is to use packet switching technology. Increasingly, public and private communications networks are being built and expanded using various packet technologies, such as Internet Protocol (IP).
A network device, such as a switch or router, typically receives, processes, and forwards or discards a packet based on one or more criteria, including the type of protocol used by the packet, addresses of the packet (e.g., source, destination, group), and type or quality of service requested. Additionally, one or more security operations are typically performed on each packet. But before these operations can be performed, a packet classification operation must typically be performed on the packet.
These operations consume time and resources, so one way to speed up their performance is to use multiple processors and to process packets in parallel. However, certain packets belonging to a stream of packets may need to be forwarded from the packet processors or even processed in the order received. Moreover, maintaining the original sequence of packets is in conflict with the desire to retire packets from a processor as soon as they are done in order to clear resources to process more packets. Desired is a way of preserving only the critical order of flows, such as, but not limited to that which does not impose arbitrary and non-optimal order between unrelated packets.